Charles is an HTTP proxy / HTTP monitor / Reverse Proxy that enables a developer to view all of the HTTP traffic between their web browser and the Internet. This includes requests, responses and the HTTP headers (which contain the cookies and caching information). View SSL communication in plain text. HTTP/1.1 support.

Charles can also simulate modem speeds by effectively throttling your bandwidth and introducing latency so that you can experience an entire website as a modem user might.

Charles is especially useful for Adobe Flash developers as you can view the contents of LoadVariables, LoadMovie and XML loads.